The invention relates to a clamping tool, comprising a base, a clamping arm articulated to the base for pivotal movement about a first pivot axis, a handle articulated to the clamping arm or the base for pivotal movement about a second pivot axis, a bridge element articulated to the handle or the clamping arm for pivotal movement about a third pivot axis, a first wedge element having a first wedge surface, said first wedge element being linearly guided on a guide, and a second wedge element having a second wedge surface facing towards the first wedge surface, said second wedge element being adapted to the first wedge element and being linearly guided, wherein in a first positional range of the handle, the first wedge surface and the second wedge surface are spaced apart from one another and wherein in a second positional range of the handle, the second wedge surface is supported on the first wedge surface and a displacement of the first wedge element drives a displacement of the second wedge element.
Toggle clamping tools are used for example to clamp workpieces in place on a machine table. The displacement capability of the first wedge element allows adjustment to accommodate different heights of workpieces to be clamped within a certain range.
U.S. Pat. No. 4,407,493 discloses a toggle clamp which is self-adjusting (“self-adjusting toggle clamp”).
Further toggle clamps are known from US 2010/0148414 A1 or WO 2010/045504 A1.
U.S. Pat. No. 2,350,034 discloses a toggle clamp having a base and an L-shaped clamping arm made of a U-shaped strap having its free ends pivotally connected to the base. The connection is at a point where a pivot bearing passes laterally through the strap ends. Furthermore, there is provided a clamping element which is located at the other end of the clamping arm. A handle has one of its ends pivotally connected to a point located in the bend of the L of the clamping arm. A link has one end pivotally connected to the base and the other end pivotally connected to the handle at a point between the pivotal connection of the handle with the clamping arm and the pivotal connection between the link and the base. When the corresponding parts are in a clamping position, the pivotal connections between one end of the link and the base, the handle with the clamping arm, and the handle with the other end of the link are aligned in one line. The pivotal connection between the handle and the other end of the link is intermediate the other of the pivotal connections. The base has provided thereon means for limiting the movement of the link and the clamping arm.
Further clamping tools are disclosed in U.S. Pat. Nos. 3,116,656, 2,531,285, 3,600,986 and 2,751,801.